From about the first quarter of the 20th century, the cigarette-making industry provided cigarettes with a rod-shaped filter attached to a tobacco rod. First, manually attached and then, from the early 1950's, mechanically attached filters became a standard component of a cigarette. The cigarette industry experimented with multi-component cigarettes and filters starting from the early 1960's. Relevant means for manufacturing such products have been revealed, e.g. in Molins invention U.S. Pat. No. 3,080,871, followed by U.S. Pat. Nos. 3,131,612, 3,267,820, 3,267,821, etc.
This and other methods and devices are discussed e.g. in Philip Morris EP1763306, highlighting various imperfections and shortcomings. This document reveals an apparatus and a method of maintaining alignment of segments in the stream of aligned segments by means of suction, or has a plurality of spaced apart separators for maintaining the alignment of segments in the stream of aligned segments, or both. Suction preventing relative movement of the segments is applied through the holes in filter segment transporting wheels, holding the segments in position as they are transferred to a continuous paper web for downstream processing. However, this arrangement allows loose segments in transit between the preceding transporting wheel and the following transporting wheel of the apparatus to remain floating in the air, jostling adjacent segments and/or the transporting means, as they become released from the suction of the preceding wheel but are not yet in the suction range of the following transporting wheel. Further, for at least some of the segment arrangements, some or all of the segments are inconsistently mechanically supported by the spacers on the circumference of the transporting wheels. Since the aligned segments are of different length, density, structure, etc., and additionally, they are manufactured within upstream production tolerances, imposing random discrepancies between them, they behave differently when in the transfer zone between the transporting wheels. Consequently, twofold transition of the loose segments between the transporting wheels in the apparatus results in random, jerky relative longitudinal movement of the segments, and displacement against one another. This results in minute, yet highly undesirable imperfections in segment alignment when discharged at the exit from the apparatus onto the continuous paper web, for downstream processing. The effect is particularly pronounced at real production speeds, where a few thousand segments are handled a minute. As compared to previous methods, the imperfections in longitudinal segment alignments were reduced but still do not allow for meeting todays quality standards of rejecting off-specification products and maintaining waste production losses. Moreover, due to the use of suction for maintaining alignment of segments during transportation towards downstream processing, this arrangement does not allow for handling fragile, low density and/or highly porous segments made of e.g. non-wrapped low-density cellulose acetate. Further, this arrangement does not allow for buffering and/or further advantageous processing of the segments to be carried out at the latest stage, and just before forming and sealing a continuous, endless rod of multi-segment rod-like articles as well known in the industry and to personnel skilled in the art.
Still further, EP2210509(A1) discloses a method of compacting, wrapping and cutting components of a rod-like articles wherein at least one of the components is a non-cleanly-cuttable component like a combustible heat source or fuel element, for example a carbonaceous heat source that remains in direct contact with the component transporting means, e.g. drums or wheels. In the disclosed method and apparatus, suction is used to hold the components, and known vacuum transfer techniques are used to transfer the components between drums. Since the revealed method requires suction or vacuum for transporting components, it is risky when transporting active powder-containing segments, e.g. heat sources, and also not suitable for transporting fragile, easily deformable, brittle components of the rod-like articles. The revealed method of compacting combustible heat source components or other chemically active compounds of the rod-like articles boosts the risk of inter-product and intra-product contamination affecting product quality, percentage of waste and overall productivity.
Also, newer methods and apparatuses described in, e.g. EP2633769, U.S. Pat. No. 8,475,348 or EP2628399, EP2653044, EP2636322, etc., disclose principles and methods of manufacturing multi-component filter rods by means of various arrangements of filter segment transfer mechanisms. Moreover, numerous patent applications within the tobacco industry reveal mechanisms and methods of forming and transferring rod-like articles, specifically filter and/or cigarette rods using a variety of drum or wheel arrangements, e.g.: GB447779, GB477908, GB662309, GB709810, GB770173, GB915203, GB1351619, GB1476931, GB1438838, WO2013076750, etc.
Until the end of the 20th century, simple, single-segment filters constituted the majority of filters produced in the tobacco industry. Over the last two decades however, more and more complex filter specifications have been developed, including multi-component, multi-segment filters, consisting of segments precisely positioned relative to the adjacent segments, with such arrangements being fitted in the final filter attached to a cigarette or to another product meant for altering physical and organoleptic properties of smoke or, generally, air mixtures passing through such articles. Hence, there is a need for developing a means of reliably manufacturing increasingly advanced and demanding multi-component filters that are frequently referred to as composite or combined filter rods.
Currently, filter specifications use a range of filter segments that include, cellulose acetate of specific density and physical structure, with such rod material being wrapped in filter paper wrapper known as plug wrap, or formed as a rod-like article without wrapping in the plug wrap (so called non-wrapped acetate), non-cellulose acetate fibrous materials, particulate materials of specific absorption and filtration properties, heat energy sources, fragrance, taste and/or other sensory attributes-modifying articles, foreign articles, e.g. liquid-containing capsules and solid objects including shaped tubular objects, bio-decomposition catalytic substances, etc. Examples of such articles are disclosed in EP0880904, U.S. Pat. Nos. 4,714,082, 5,819,751, 5,040,551, 8,528,567, WO2011042175, WO2012000646, WO2013068081, EP1972213, EP2462822, etc.
Thus, in order to administer such substances in any required combination, and align them into a continuous rod-like article in a precisely pre-determined and recurrent manner, not affecting quality of any of the finished filter components, and with highly repeatable overall quality of the final filter product, an apparatus and method of achieving these goals is described in the disclosed invention.